The hydrides of Group VI elements are molecular. Except for water whose molecules are held together by hydrogen bonds 3.29), the molecules of these hydrides are held together in the liquid state by van der Waals forces and dipole-dipole attraction. The Van der Waals forces become stronger with increasing mass from H S to H Te (Figure 3.30). Water should H have the lowest boiling point, but it has the highest boiling point because of relatively strong hydrogen bonds between its molecules.